Thursday, October 6, 2016

The release v2.29 (now rc1) is without dramatical changes, the small exception
is libsmartcols where we have many improvements.

The old good cal(1) is more user-friendly now. It's possible to specify month
by name (e.g. "cal January 2017") and use relative placeholders, for example:

cal now
cal '1 year ago'
cal '+2 months'

fdisk(8) allows to wipe newly created partitions -- the feature is possible to
control by new command line option --wipe-partitions[==auto|never|default].

The
default in the interactive mode is to ask user when a filesystem or RAID signature
is detected. The goal is to be sure that new block devices are usable without
any collisions and extra wipefs(8) step (because users are lazy and mkfs-like
programs are often no smart enough to wipe the device).

findmnt --verify is probably the most attractive new feature for admins. The
command scans /etc/fstab and tries to verify the configuration. The traditional
way is to use "mount -a" for this purpose, but it's overkill. The new --verify
does not call mount(2), but it checks parsability, LABEL/UUID/etc.
translation to paths, mountpoints order, support for specified FS types.
The option --verify together with --verbose provides many details.

When you create multiple loop block devices from
one backing file then Linux kernel does not care about possible collisions
and the same on-disk filesystem is maintained by multiple independent in-memory
filesystem instances. The result is obvious -- data lost and filesystem damage.

Now mount(8) rejects requests to create another device and mount filesystem for the same backing file.
The command losetup --nooverlap reuse loop device if already exists for the
same backing file. All the functionality calculate with offset and sizelimit
options of course, so it's fine to have multiple regions (partitions) in the same image file and mount all of them in the same time. The restriction is that the regions should not overlap. Thanks to Stanislav Brabec from Suse!

Heiko Carstens from IBM (thanks!) has improved lscpu(1) for s390. Now it supports
"drawer" topology level, static and dynamic MHz, machine type and a new option
--physical.

The most important libsmartcols change is probably better support for
multi-line cells. Now the library supports custom cell wrap functions -- this
allows to wrap your text in cells after words, line breaks, etc.
See multi-line cells (WRAPNL column) output:

The idea
is to use libsmartcols as output formatter for Fedora/RHEL dnf (package manager
for RPM-based Linux distributions, yum replacement). This is also reason why
libsmartcols has been massively extended and improved in the last releases.

Tuesday, March 22, 2016

The release v2.28 does not contain any dramatical changes and huge
improvements. It's another release to keep users happy and absorb new features
provided by kernel. We all love this kind of release, right? :-)

The fdisk programs (sfdisk, cfdisk and fdisk) have been improved to wipe old filesystem, RAID and
partition tables from the device before libfdisk writes a new partition table.

The fdisk-like programs traditionally care about begin of the device, but it's
insufficient. This new feature has been introduced to avoid collisions between
new partition table and old unwanted signatures and it's possible to control
it by --wipe[=auto|never|always]. For backward compatibility on non-terminals
(non interactive fdisk execution) the feature is disabled by default.

Linux kernel 3.14 is really not a hot news, but standard Linux userspace still does not
support DEADLINE scheduler. chrt since v2.28 supports the DEADLINE scheduling class and
the new options --sched-runtime --sched-period and --sched-deadline.

The command logger supports RFC 5424 structured data through the new options
--sd-id and --sd-param. For example:

The library libsmartcols has been massively improved (thanks to Igor Gnatenko
for testing and reviews). Now it's possible to specify title for table, table
supports multi-line cells, it's possible to print subset of table and the
library supports continuous printing.

The portability of the util-linux package is not our primary goal, but in many
cases port code to the another libc or another operation system (if possible)
is a way how to detect code disadvantages, obsolete functions etc. v2.28 is
possible to compile on OSX and improved has been also support for kFreeBSD and GNU Hurd (of
course you cannot compile Linux specific stuff, but build-system is smart
enough to automatically disable utils irrelevant for your OS).

This is in
connection with our regression tests suite, where many things have been
improved to make the tests more stable in all random environments.
(thanks to Ruediger Meier).